1. Technical Field
This invention relates to improvements in a key and a lock device of an axial-pin disk-tumbler type, especially those configured in combination with a handgun lock device such as disclosed in the co-pending U.S. patent application Ser. No. 10/820,987 of Ha. More particularly the invention relates to improvements in the key and the means for receiving the key within the lock device and the manufacturing methods thereof.
2. Description of the Related Art
A particular gunlock device disclosed and claimed by the co-pending U.S. Patent application of Ha listed in the Cross Reference to Related Applications section and referred to hereunder as prior art is specifically configured for use on a loaded and attended firearm. For example, a duty handgun of a law enforcement officer may be maintained in a loaded condition and kept in the holster, but protected with the gun-lock device to alleviate the possibility of it being intercepted by a criminal during an arrest and have it used against the officer. Also, a law-abiding citizen may keep his handgun loaded and at easy reach within his premises for defense use against impending danger, but have the gun protected with the gun-lock device to prevent from an accidental discharge resulting from mishandling by any of his family members. For these and many other scenerios where the firearm is attended, the most important characteristic for the gun-lock device should be that it lend itself to be quickly and reliably unlocked by the authorized user in those times of need without requiring a great deal of mental coordination (to remember where the key is or what the combination number is) or manual dexterity from the user to negotiate the unlocking operation. Since the firearm will be maintained within a close proximity and under cognizance of the owner at all times, the level of security required of the lock device, for example the strength of the lock casing or the lock mechanism's resistance to being picked, would rank distant second.
The co-pending U.S. Patent application of Ha elaborates on many advantages of a key operated gun-lock device of an axial-pin, disk-tumbler type over those of other types and discloses and claims such a gun-lock device in combination with a special ring-mounted key. Such key may be worn by the user and, thus at any time, made immediately available for the user to unlock the lock device. To satisfactorily serve dual role as both the key and a ring, the ring-mounted key must meet several objectives beyond that primary functional objective of unlocking the lock device. First, the ring-mounted key must be visually attractive for the user to be willing to wear it for extended periods. Second, key portion should be sufficiently strong to endure common use as a ring and survive without damage any reasonable magnitude of physical abuse exerted thereupon. Third, the overall shape of the key should be reasonably inconspicuous to the eyes of the others so as not to draw unwarranted attention to it when it is plainly worn by the user. Fourth, and foremost as a key used in combination with a gun-lock device, the key and the receiving lock assembly should allow for a speedy and reliable insertion of the key into the lock assembly using only of the user's tactile senses and without a high degree of manual dexterity. Fifth, the physical design of the key must lend itself to be manufactured easily and inexpensively using conventional fabrication methods available in the industry.
A particular key design presented by the co-pending U.S. Patent application of Ha comprises a set of finger-like cylindrical projections symmetrically disposed about a conical pillar centrally placed on the key body. The finger-like projections are slender pins which are individually press-fitted into the mating holes prepared into the key body and are subsequently trimmed to predetermined individual heights as required for proper cooperation with the lock assembly. The operation of an axial-pin disk-tumbler type lock device with regard to how the key interacts with the tumbler pins within the lock to unlock the device is well known in the art and will be discussed further in the foregoing section, Detailed Description of the Invention.
A key so constructed as described above and hereinafter referred to as “prior art key of Ha” is shown in FIG. 13 and FIG. 14 of the drawings. In consideration with regard to the five objectives for a ring-mounted key discussed above, the prior art key of Ha is visually attractive. Also, during the key-insertion into the lock, the centrally placed conical pillar would quickly find its way into the mating recess at the receiving face of the lock assembly, and thus, the key would self-guide and allow speedy and reliable engagement with the lock. The prior art key of Ha therefore satisfies two of the five objectives. However, because the individual fingers have slender proportions and are supported only at the base, they are insufficiently guarded against normal physical abuse inflicted thereupon resulting from common use as a ring. Additionally, these individually standing fingers cast an extraordinary appearance inconsistent with modern jewelry designs, and thus would elevate conspicuity. Lastly, the prior art key would be relatively difficult and costly to manufacture. The manufacturing procedure would involve, first, precision machining operation to prepare correctly sized and positioned holes in the key body to receive the individual pins, then, a great deal of skill and care would be required during the manual press-fit operation to ensure that these pins are installed straight and not bent nor buckled. If these pins are not correctly installed the key would not be received into the mating keyway on the face of the lock assembly.
During the search for a key design better suited for a ring-mounted application, a traditional, hollow cylindrical key used with commercially available conventional disk-tumbler type lock was considered. This key design typically includes a set of semi-circular or semi-rectangular recesses machined along the outer circumference of the hollow cylindrical body and are controlled to predetermined individual depths along the longitudinal axis of the key body for proper cooperation with the tumbler pins within the mating lock assembly. A key of this type is well known by the general public and are shown and sufficiently described in detail in such prior art Patents of Hughes, Kerr, and Christopher, herein listed as the References Cited. In consideration with regard to the five objectives for a ring-mounted key discussed above, first, the traditional hollow cylindrical key is not aesthetically pleasing. However, second, its one-piece cylindrical construction is durable and should not easily incur damaged from normal physical abuse resulting from common use as a ring. Third, because the key design of this type is so well known by the general public, it will immediately be recognized as a key of sort and generate unwarranted attention. Fourth, the physical designs of the hollow cylindrical key and the mating conventional disk-tumbler lock do not incorporate any specific guiding features aimed at facilitating the key-to-lock alignment during the key insertion process. In fact, it is well known from experience, a close sight and manual coordination is required during the operation of a lock and key of this type in order to correctly align and insert the key into the lock assembly. Fifth, the hollow cylindrical key may be easily and inexpensively manufactured. Thus, the traditional hollow cylindrical key design of the conventional disk tumbler lock device meets two of the five above discussed objectives for a ring-mounted key. However, it fails to satisfy the most important criteria for a key used in combination with such gun-lock device as mentioned, as it does not lend itself to a speedy and tactile-only key-to-lock engagement operation.